Direct Medical Costs of Four Vaccine-Preventable Infectious Diseases in Older Adults in Spain

Cost-benefit analysis of the National Immunization Program in Spain

Broad benefits of vaccination programs are well acknowledged but difficult to measure, especially when considering all vaccines included in a National Immunization Program (NIP). The aim was to conduct a cost-benefit analysis of the entire NIP in Spain, and an expanded NIP including four potential additional programs. A cost-benefit analysis was performed in Excel to assess the economic and health benefits (€) of vaccinating a single cohort of newborns over a lifetime horizon compared to no vaccination, from a societal perspective: firstly, according to the 2020 NIP in Spain (including 2021 recommendation for herpes zoster in 65-year-olds); and secondly, with an expanded NIP (adding rotavirus and meningococcal B in infants, and pertussis booster in adults aged >65 years and herpes zoster in all adults >50 years). The main inputs were taken from published literature and Spanish databases. Results were presented as a benefit-cost ratio (economic benefit per €1 invested). A cohort of 343,126 newborns were included in the analysis. The total investment needed to vaccinate the cohort throughout their lifetime, according to the 2020 NIP and the expanded NIP, was estimated at €168.5 million and €275.5 million, respectively. Potential economic benefits were €772.2 million and €803.0 million, respectively. The societal benefit-cost ratio was €4.58 and €2.91 per €1 invested, respectively. Even with the addition of new vaccination programs, the Spanish NIP yielded positive benefit-cost ratios from the societal perspective, demonstrating that NIPs spanning the full life course are an efficient public health measure.

Impact of twelve immunization-preventable infectious diseases on population health using disability-adjusted life years (DALYs) in Spain

BACKGROUND

The objective of this study is to estimate the burden of selected immunization-preventable infectious diseases in Spain using the Burden of Communicable Diseases in Europe (BCoDE) methodology, as well as focusing on the national immunization programme and potential new inclusions.

METHODS

The BCoDE methodology relies on an incidence and pathogen-based approach to calculate disease burden via disability-adjusted life year (DALY) estimates. It considers short and long-term sequelae associated to an infection via outcome trees. The BCoDE toolkit was used to populate those trees with Spanish-specific incidence estimates, and de novo outcome trees were developed for four infections (herpes zoster, rotavirus, respiratory syncytial virus [RSV], and varicella) not covered by the toolkit. Age/sex specific incidences were estimated based on data from the Spanish Network of Epidemiological Surveillance; hospitalisation and mortality rates were collected from the Minimum Basic Data Set. A literature review was performed to design the de novo models and obtain the rest of the parameters. The methodology, assumptions, data inputs and results were validated by a group of experts in epidemiology and disease modelling, immunization and public health policy.

RESULTS

The total burden of disease amounted to 163.54 annual DALYs/100,000 population. Among the selected twelve diseases, respiratory infections represented around 90% of the total burden. Influenza exhibited the highest burden, with 110.00 DALYs/100,000 population, followed by invasive pneumococcal disease and RSV, with 25.20 and 10.57 DALYs/100,000 population, respectively. Herpes zoster, invasive meningococcal disease, invasive Haemophilus influenza infection and hepatitis B virus infection ranked lower with fewer than 10 DALYs/100,000 population each, while the rest of the infections had a limited burden (< 1 DALY/100,000 population). A higher burden of disease was observed in the elderly (≥ 60 years) and children < 5 years, with influenza being the main cause. In infants < 1 year, RSV represented the greatest burden.

CONCLUSIONS

Aligned with the BCoDE study, the results of this analysis show a persisting high burden of immunization-preventable respiratory infections in Spain and, for the first time, highlight a high number of DALYs due to RSV. These estimates provide a basis to guide prevention strategies and make public health decisions to prioritise interventions and allocate healthcare resources in Spain.

#SharingHEOR: Developing Modern Media for Communication and Dissemination of Health Economics and Outcomes Research

Questions regarding the effectiveness and safety of health interventions and allocation of health care resources are frequently discussed in mainstream and social media. Additionally, government and foundation funders are increasingly mandating that results be disseminated to the lay public and patients may benefit from being able to digest scientific research regarding their health conditions. Therefore, it is important to widely disseminate and clearly communication health economics and outcomes research (HEOR) findings to a range of interested parties. Digital media features such as graphical or visual abstracts, infographics and videos are informative and add value to research articles by improving reader engagement with articles, potentially increasing their impact, and allowing results to be more widely disseminated. However, use of novel digital media for research dissemination has been relatively limited to date. In this article, we discuss the rationale for developing novel media to communicate and disseminate research findings and offer practical advice for doing so. We conclude by outlining a future agenda for research regarding HEOR communication and dissemination.

The Cost of Seasonal Influenza: A Systematic Literature Review on the Humanistic and Economic Burden of Influenza in Older (≥ 65 Years Old) Adults

INTRODUCTION

Adults aged ≥ 65 years contribute a large proportion of influenza-related hospitalizations and deaths due to increased risk of complications, which result in high medical costs and reduced health-related quality of life (HRQoL). Although seasonal influenza vaccines are recommended for older adults, the effectiveness of current vaccines is dependent on several factors including strain matching and recipient demographic factors. This systemic literature review aimed to explore the economic and humanistic burden of influenza in adults aged ≥ 65 years.

METHODS

An electronic database search was conducted to identify studies assessing the economic and humanistic burden of influenza, including influenza symptoms that impact the HRQoL and patient-related outcomes in adults aged ≥ 65 years. Studies were to be published in English and conducted in Germany, France, Spain, and Italy, the UK, USA, Canada, China, Japan, Brazil, Saudi Arabia, and South Africa.

RESULTS

Thirty-eight studies reported on the economic and humanistic burden of influenza in adults aged ≥ 65 years. Higher direct costs were reported for people at increased risk of influenza-related complications compared to those at low risk. Lower influenza-related total costs were found in those vaccinated with adjuvanted inactivated trivalent influenza vaccine (aTIV) compared to high-dose trivalent influenza vaccine (TIV-HD). Older age was associated with an increased occurrence and longer duration of certain influenza symptoms.

CONCLUSION

Despite the limited data identified, results show that influenza exerts a high humanistic and economic burden in older adults. Further research is required to confirm findings and to identify the unmet needs of current vaccines.

Understanding the Global Burden of Influenza in Adults Aged 18-64 years: A Systematic Literature Review from 2012 to 2022

INTRODUCTION

Adults aged 18-64 years comprise most of the working population, meaning that influenza infection can be disruptive, causing prolonged absence from the workplace, and reduced productivity and the ability to care for dependents. Influenza vaccine uptake is relatively low, even among the older adults in this population (i.e., aged 50-64 years), reflecting a lack of perceived need for vaccination. This systematic literature review (SLR) aimed to characterize the global burden of influenza in the 18-64 years population.

METHODS

An electronic database search was conducted and supplemented with conference and gray literature searches. Eligible studies described at least one of clinical, humanistic, or economic outcomes in adults aged 18-64 years and conducted across several global regions. Included studies were published in English, between January 1, 2012, and September 20, 2022.

RESULTS

A total of 40 publications were included, with clinical, humanistic, and economic outcomes reported in 39, 5, and 15, respectively. Risk of influenza-associated clinical outcomes were reported to increase with age among the 18-64 years population, including hospitalizations (Yamana et al. in Intern Med 60:3401-3408, 2021; Derqui et al. in Influenza Other Respir Viruses 16:862-872, 2022; Fuller et al. in Influenza Other Respir Viruses 16:265-275, 2022; Ortiz et al. in Crit Care Med 42:2325-2332, 2014; Yandrapalli et al. in Ann Transl Med 6:318, 2018; Zimmerman et al. in Influenza Other Respir Viruses 16:1133-1140, 2022). ICU admissions, mortality, ER/outpatient visits, and use of mechanical ventilation were recorded. Adults aged 18-64 years with underlying comorbidities were at higher risk of influenza-related hospitalizations, ICU admission, and mortality than otherwise healthy individuals. Length of hospital stay increased with age, although a lack of stratification across other economic outcomes prevented identification of further trends across age groups.

CONCLUSIONS

High levels of hospitalization and outpatient visits demonstrated a clinical influenza-associated burden on patients and healthcare systems, which is exacerbated by comorbidities. Considering the size and breadth of the general population aged 18-64 years, the limited humanistic and economic findings of this SLR likely reflect an underreported burden. Greater investigation into indirect costs and prolonged absenteeism associated with influenza infection is required to fully understand the economic burden in this population.

Cost-utility analysis of the use of the 20-valent anti-pneumococcal vaccine (PCV20) in adults older than 60 years in Spain

BACKGROUND AND OBJECTIVES

A cost-utility analysis was conducted to assess the efficiency of implementing a PCV20 vaccination strategy in the Spanish adult population older than 60 years, for the prevention of non-bacteremic pneumococcalpneumonia (NBP) and invasive pneumococcal disease (IPD).

METHODS

A Markov model, with annual cycles and a time horizon of 10 years was used. The analysis population was stratified by age and risk groups. The comparator was the sequential vaccination with the 15-valent pneumococcal conjugate vaccine (PCV15) followed by one dose of the pneumococcal polysaccharide vaccine (PPV23). The base case analysis was performed from the National Healthcare System (NHS) perspective including direct costs (€2018) and applying a discount of 3% to future costs and outcomes. Alternative scenarios explored a shorter time horizon (5 years), the societal perspective and other available vaccination strategies. All the parameters and assumptions were validated by a panel of experts. To evaluate the robustness of the model, deterministic and probabilistic sensitivity analyses (PSA) were carried out.

RESULTS

The results of the study showed that the vaccination strategy with PCV20 is a dominant option compared to the sequential regimen (PCV15 + PPSV23), resulting in direct cost savings of €85.7 M over 10 years, with a small increase in quality-adjusted life years (QALYs). PCV20 vaccination avoided 2,161 cases of IPD, 19,470 of NBP and 3,396 deaths and according to the PSA, the probability of PCV20 being cost-effective compared to a sequential regimen (PCV15 + PPSV23) was 100%.

CONCLUSIONS/RECOMMENDATIONS

In the Spanish adult population older than 60 years, the vaccination strategy with one dose of PCV20 is more effective and less expensive (dominant) than vaccination with a sequential schedule with PCV15 and PPSV23.

Excess hospitalizations and mortality associated with seasonal influenza in Spain, 2008-2018

BACKGROUND

Influenza may trigger complications, particularly in at-risk groups, potentially leading to hospitalization or death. However, due to lack of routine testing, influenza cases are infrequently coded with influenza-specific diagnosis. Statistical models using influenza activity as an explanatory variable can be used to estimate annual hospitalizations and deaths associated with influenza. Our study aimed to estimate the clinical and economic burden of severe influenza in Spain, considering such models.

METHODS

The study comprised ten epidemic seasons (2008/2009-2017/2018) and used two approaches: (i) a direct method of estimating the seasonal influenza hospitalization, based on the number of National Health Service hospitalizations with influenza-specific International Classification of Diseases (ICD) codes (ICD-9: 487-488; ICD-10: J09-J11), as primary or secondary diagnosis; (ii) an indirect method of estimating excess hospitalizations and deaths using broader groups of ICD codes in time-series models, computed for six age groups and four groups of diagnoses: pneumonia or influenza (ICD-9: 480-488, 517.1; ICD-10: J09-J18), respiratory (ICD-9: 460-519; ICD-10: J00-J99), respiratory or cardiovascular (C&R, ICD-9: 390-459, 460-519; ICD-10: I00-I99, J00-J99), and all-cause. Means, excluding the H1N1pdm09 pandemic (2009/2010), are reported in this study.

RESULTS

The mean number of hospitalizations with a diagnosis of influenza per season was 13,063, corresponding to 28.1 cases per 100,000 people. The mean direct annual cost of these hospitalizations was €45.7 million, of which 65.7% was generated by patients with comorbidities. Mean annual influenza-associated C&R hospitalizations were estimated at 34,894 (min: 16,546; max: 52,861), corresponding to 75.0 cases per 100,000 (95% confidence interval [CI]: 63.3-86.3) for all ages and 335.3 (95% CI: 293.2-377.5) in patients aged ≥ 65 years. We estimate 3.8 influenza-associated excess C&R hospitalizations for each hospitalization coded with an influenza-specific diagnosis in patients aged ≥ 65 years. The mean direct annual cost of the estimated excess C&R hospitalizations was €142.9 million for all ages and €115.9 million for patients aged ≥ 65 years. Mean annual influenza-associated all-cause mortality per 100,000 people was estimated at 27.7 for all ages.

CONCLUSIONS

Results suggest a relevant under-detected burden of influenza mostly in the elderly population, but not neglectable in younger people.

Vaccination against Community-Acquired Pneumonia in Spanish Adults: Practical Recommendations by the NeumoExperts Prevention Group

In the adult population, community-acquired pneumonia (CAP) is a serious disease that is responsible for high morbidity and mortality rates, being frequently associated with multidrug resistant pathogens. The aim of this review is to update a practical immunization prevention guideline for CAP in Spain caused by prevalent respiratory pathogens, based on the available scientific evidence through extensive bibliographic review and expert opinion. The emergence of COVID-19 as an additional etiological cause of CAP, together with the rapid changes in the availability of vaccines and recommendations against SARS-CoV-2, justifies the need for an update. In addition, new conjugate vaccines of broader spectrum against pneumococcus, existing vaccines targeting influenza and pertussis or upcoming vaccines against respiratory syncytial virus (RSV) will be very useful prophylactic tools to diminish the burden of CAP and all of its derived complications. In this manuscript, we provide practical recommendations for adult vaccination against the pathogens mentioned above, including their contribution against antibiotic resistance. This guide is intended for the individual perspective of protection and not for vaccination policies, as we do not pretend to interfere with the official recommendations of any country. The use of vaccines is a realistic approach to fight these infections and ameliorate the impact of antimicrobial resistance. All of the recently available scientific evidence included in this review gives support to the indications established in this practical guide to reinforce the dissemination and implementation of these recommendations in routine clinical practice.

Clinical and economic burden of physician-diagnosed influenza in adults during the 2017/2018 epidemic season in Spain

BACKGROUND

Influenza is an acutely debilitating respiratory infection, contributing significantly to outpatient visits and hospitalizations. Spain lacks comprehensive and updated data on the burden of influenza, particularly in the outpatient setting. Our study aimed to fill this gap by estimating the clinical and economic burden of physician-diagnosed influenza cases in adults from four Spanish regions, stratified by age groups and presence of comorbidities.

METHODS

A retrospective cost-of-illness study was conducted using data from an electronic medical records database from the National Healthcare Service (NHS) of four Spanish regions for individuals aged ≥ 18 years diagnosed for influenza during the 2017/2018 epidemic season. Health resource utilization and related cost data were collected, including primary care visits, referrals to other specialists, visits to the emergency department, hospitalizations, and prescribed medicines.

RESULTS

The study reported a total of 28,381 patients aged ≥ 18 years diagnosed with influenza, corresponding to 1,804 cases per 100,000 population. Most patients were aged < 65 years: 60.5% (n = 17,166) aged 18-49 and 26.3% (n = 7,451) 50-64 years. A total of 39.2% (n = 11,132) of patients presented a comorbidity. Cardiovascular diseases were the most common comorbidity reported along with influenza. The mean healthcare cost per case was estimated at €235.1 in population aged 18-49 years, increasing by 1.7 and 4.9 times in those aged 50-64 (€402.0) and ≥ 65 (€1,149.0), respectively. The mean healthcare cost per case was 3.2 times higher in patients with comorbidities. The total healthcare cost of medically attended influenza cases was mainly driven by primary care (45.1%) and hospitalization (42.0%). Patients aged 18-64 years old accounted for 61.9% of the costs of medically attended influenza. Irrespective of age, patients with comorbidities accounted for 67.1% of costs.

CONCLUSIONS

Season 2017/2018 was associated with a considerable burden of influenza in Spain, which increased with age and presence of comorbidities. Individuals with comorbidities accounted for most of the costs of influenza. Results suggest that population aged 18-64 years old is generating the highest share of costs to the NHS when all healthcare costs are considered. Preventive strategies targeting subjects with comorbidities, regardless of age, should be warranted.